US personnel flown out of country as reports claim ‘extraordinary and unprecedented’ security measures in force in capital Sana’a

Yemeni security forces have been put on high alert amid warnings of an imminent attack by al-Qaida in Sana’a, as the US and Britain withdrew embassy staff and urged their citizens to leave the country.

BBC Arabic quoted a Yemeni security source as saying that “extraordinary and unprecedented” security measures had been put in place, with armoured vehicles deployed at the presidential palace and other sensitive government and foreign installations in Yemen’s capital.

Dozens of al-Qaida operatives were said to have streamed into Sana’a in the last few days, apparently to take part in a terrorist attack, the BBC said. The Yemeni claim could not be independently confirmed.

Congress told that NSA monitoring led to interception of al-Qaida threats but privacy campaigners fear ulterior political motives

US embassies in the Middle East are to remain closed for the rest of the week as supporters of the National Security Agency’s sweeping surveillance powers used the unspecified terror alert to bolster the case against reining in the controversial measures.

The closures follow the alleged interception of al-Qaida communications in Yemen, which intelligence committee members in Congress have been told were collected overseas using powers granted to the NSA under the Foreign Intelligence Surveillance Act – not the bulk surveillance programs disclosed by the Guardian and the Washington Post thanks to whistleblower Edward Snowden.

A privacy group questioned the publicity given to the latest alert after the State Department announced on Sunday evening that the number of embassies and consulates closed “out of an abundance of caution”

would be increased, with some remaining shut for up to a week.

Rebublican senator Saxby Chambliss said the NSA had identified threats that were the most serious for years and akin to levels of “terrorist chatter” picked up before 9/11.

On Democracy Now!, journalist for The Guardian, Glenn Greenwald discusses the latest terrorist treats and the closings ogf US embassies int the the region.

The Obama administration has announced it will keep 19 diplomatic posts in North Africa and the Middle East closed for up to a week, due to fears of a possible militant threat. On Sunday, Senator Saxby Chambliss, the top Republican on the Senate Intelligence Committee, said the decision to close the embassies was based on information collected by the National Security Agency. “If we did not have these programs, we simply would not be able to listen in on the bad guys,” Chambliss said, in a direct reference to increasing debate over widespread spying of all Americans revealed by Glenn Greenwald of The Guardian. “Nobody has ever questioned or disputed that the U.S. government, like all governments around the world, ought to be eavesdropping and monitoring the conversations of people who pose an actual threat to the United States in terms of plotting terrorist attacks,” Greenwald says.